The present invention relates to passive infra-red motion detectors of the type used in residential outdoor lighting fixtures, for example, to illuminate a walkway or driveway when a person or automobile approaches. The invention is more particularly directed to a decorative lighting fixture in which the range monitored by the motion detector can be selected by the user.
Decorative lighting fixtures that are activated by passive infra-red (PIR) motion detectors have been available for some time. The motion detectors in these fixtures may be located in a variety of places. When decorative motion-activated fixtures were first introduced, the motion detectors were located in the so-called backplate, which is a mounting plate used to mount the fixture on a wall. Later, decorative fixture designs emerged in which the motion detector was included in the body of the fixture itself. In some designs the presence of the motion detector was apparent but the motion detector housing was embellished so as to complement the overall decorative appearance. In other fixture designs the motion detector was hidden in the body of the fixture so that its presence was not readily noticeable.
Decorative fixtures are used in a variety of settings that cannot all be handled equally well by a single fixed motion detector. For example, if the fixture is mounted by the front door of a house which is elevated above the street level, then the motion detector will have to look downward to monitor a walkway coming up to the front door. If the house is situated below the street level, then the motion detector will have to look upward somewhat to adequately monitor the walkway. Even for houses located at the street level, houses set back more will want a longer range field of view than those situated closer to the street. A number of decorative fixtures have addressed this problem by providing for some adjustment of the motion detector field of view. Examples of such decorative fixtures may be seen in the following U.S. Pat. Nos. 5,757,004 to Sandell et al.; 6,323,488 to McCavit et al.; 6,376,840 to Ko; and 6,943,687 to Lee et al.